MIPS: Add RTC support for Loongson1C board

The patch adds RTC support for Loongson1C board, and enable the external
crystal when the RTC is first powered up.

Signed-off-by: Yang Ling <gnaygnil@gmail.com>
Cc: keguang.zhang@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14214/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

4 files changed, 19 insertions, 6 deletions

diff --git a/arch/mips/include/asm/mach-loongson32/platform.h b/arch/mips/include/asm/mach-loongson32/platform.h
index 672531aa9bef..7adc31364939 100644
--- a/arch/mips/include/asm/mach-loongson32/platform.h
+++ b/arch/mips/include/asm/mach-loongson32/platform.h
@@ -30,5 +30,6 @@ void __init ls1x_clk_init(void);
 void __init ls1x_dma_set_platdata(struct plat_ls1x_dma *pdata);
 void __init ls1x_nand_set_platdata(struct plat_ls1x_nand *pdata);
 void __init ls1x_serial_set_uartclk(struct platform_device *pdev);
+void __init ls1x_rtc_set_extclk(struct platform_device *pdev);
 
 #endif /* __ASM_MACH_LOONGSON32_PLATFORM_H */
diff --git a/arch/mips/loongson32/common/platform.c b/arch/mips/loongson32/common/platform.c
index 4d12e365dcb0..beff0852c6a4 100644
--- a/arch/mips/loongson32/common/platform.c
+++ b/arch/mips/loongson32/common/platform.c
@@ -23,6 +23,10 @@
 #include <dma.h>
 #include <nand.h>
 
+#define LS1X_RTC_CTRL   ((void __iomem *)KSEG1ADDR(LS1X_RTC_BASE + 0x40))
+#define RTC_EXTCLK_OK   (BIT(5) | BIT(8))
+#define RTC_EXTCLK_EN   BIT(8)
+
 /* 8250/16550 compatible UART */
 #define LS1X_UART(_id)                                          \
         {                                                       \
@@ -66,6 +70,15 @@ void __init ls1x_serial_set_uartclk(struct platform_device *pdev)
                 p->uartclk = clk_get_rate(clk);
 }
 
+void __init ls1x_rtc_set_extclk(struct platform_device *pdev)
+{
+        u32 val;
+
+        val = __raw_readl(LS1X_RTC_CTRL);
+        if (!(val & RTC_EXTCLK_OK))
+                __raw_writel(val | RTC_EXTCLK_EN, LS1X_RTC_CTRL);
+}
+
 /* CPUFreq */
 static struct plat_ls1x_cpufreq ls1x_cpufreq_pdata = {
         .clk_name       = "cpu_clk",
diff --git a/arch/mips/loongson32/ls1c/Makefile b/arch/mips/loongson32/ls1c/Makefile
index 891eac482b82..a92c6cd3418d 100644
--- a/arch/mips/loongson32/ls1c/Makefile
+++ b/arch/mips/loongson32/ls1c/Makefile
@@ -1,5 +1,5 @@
 #
-# Makefile for loongson1B based machines.
+# Makefile for loongson1C based machines.
 #
 
 obj-y += board.o
diff --git a/arch/mips/loongson32/ls1c/board.c b/arch/mips/loongson32/ls1c/board.c
index 3d69bd63ad56..a96bed5e3ea6 100644
--- a/arch/mips/loongson32/ls1c/board.c
+++ b/arch/mips/loongson32/ls1c/board.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016 Ling Yang <gnaygnil@gmail.com>
+ * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -12,17 +12,16 @@
 static struct platform_device *ls1c_platform_devices[] __initdata = {
         &ls1x_uart_pdev,
         &ls1x_eth0_pdev,
+        &ls1x_rtc_pdev,
 };
 
 static int __init ls1c_platform_init(void)
 {
-        int err;
-
         ls1x_serial_set_uartclk(&ls1x_uart_pdev);
+        ls1x_rtc_set_extclk(&ls1x_rtc_pdev);
 
-        err = platform_add_devices(ls1c_platform_devices,
+        return platform_add_devices(ls1c_platform_devices,
                                    ARRAY_SIZE(ls1c_platform_devices));
-        return err;
 }
 
 arch_initcall(ls1c_platform_init);